Alexander V. Sergienko

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We report on a high-intensity source of polarization-entangled photon pairs with high momentum definition. Type-II noncollinear phase matching in parametric down conversion produces true entanglement: No part of the wave function must be discarded, in contrast to previous schemes. With two-photon fringe visibilities in excess of 97%, we demonstrated a(More)
We demonstrate that two recent innovations in the field of practical quantum key distribution (one-way autocompensation and passive detection) are closely related to the methods developed to protect quantum computations from decoherence. We present a new scheme that combines these advantages, and propose a practical implementation of this scheme that is(More)
Quantum optical coherence tomography (QOCT) makes use of an entangled twin-photon light source to carry out axial optical sectioning. We have probed the longitudinal structure of a sample comprising multiple surfaces in a dispersion-cancelled manner while simultaneously measuring the group-velocity dispersion of the interstitial media between the reflecting(More)
Entangled-photon pairs ~biphotons! generated by spontaneous optical parametric down-conversion exhibit a number of properties that are analogous to those of ordinary photons generated by incoherent sources. The spatial pump-field distribution and the two-particle wave function in the biphoton case play the respective roles of the source intensity(More)
The use of entangled photons in an imaging system can exhibit effects that cannot be mimicked by any other two-photon source, whatever the strength of the correlations between the two photons. We consider a two-photon imaging system in which one photon is used to probe a remote (transmissive or scattering) object, while the other serves as a reference. We(More)
A periodically poled lithium niobate (PPLN) crystal has been used as an efficient source of non-collinearly generated polarization-entangled photon pairs at 810 and 1550 nm. The PPLN crystal was endowed with a specially designed poling pattern and the entangled photons were generated via the nonlinear optical process of spontaneous parametric down(More)
Mark C. Booth,* Mete Atatüre, Giovanni Di Giuseppe, Bahaa E. A. Saleh, Alexander V. Sergienko, and Malvin C. Teich Quantum Imaging Laboratory, Department of Biomedical Engineering, Boston University, 8 Saint Mary’s Street, Boston, Massachusetts 02215 Quantum Imaging Laboratory, Department of Physics, Boston University, 8 Saint Mary’s Street, Boston,(More)
We present a scheme for generating polarization-entangled photons pairs with arbitrary joint spectrum. Specifically, we describe a technique for spontaneous parametric down-conversion in which both the center frequencies and the bandwidths of the down-converted photons may be controlled by appropriate manipulation of the pump pulse. The spectral control(More)
We experimentally demonstrate an approach for manipulating the spectral profiles of entangled-photon pairs. The spectral properties are determined by selecting both the appropriate spatial profile of the pump laser radiation and the geometry of the noncollinear spontaneous parametric downconversion. Both spectra, the spectrum of the individual signal and(More)